funcnode.cc

   1 #include "funcnode.h"
   2
   3 FuncNode::FuncNode(ModelHistory * history) :
   4         history(history),
   5         predicate_tree_initialized(false),
   6         exit_count(0),
   7         func_inst_map(),
   8         inst_list(),
   9         entry_insts(),
  10         action_list_buffer(),
  11         predicate_tree_position()
  12 {
  13         predicate_tree_entry = new Predicate(NULL, true);
  14         predicate_tree_entry->add_predicate_expr(NOPREDICATE, NULL, true);
  15
  16         // memories that are reclaimed after each execution
  17         read_locations = new loc_set_t();
  18         val_loc_map = new HashTable<uint64_t, loc_set_t *, uint64_t, 0>();
  19         loc_may_equal_map = new HashTable<void *, loc_set_t *, uintptr_t, 0>();
  20         thrd_inst_act_map = new SnapVector<inst_act_map_t *>();
  21
  22         //values_may_read_from = new value_set_t();
  23 }
  24
  25 /* Reallocate snapshotted memories when new executions start */
  26 void FuncNode::set_new_exec_flag()
  27 {
  28         for (mllnode<FuncInst *> * it = inst_list.begin(); it != NULL; it = it->getNext()) {
  29                 FuncInst * inst = it->getVal();
  30                 inst->unset_location();
  31         }
  32
  33         read_locations = new loc_set_t();
  34         val_loc_map = new HashTable<uint64_t, loc_set_t *, uint64_t, 0>();
  35         loc_may_equal_map = new HashTable<void *, loc_set_t *, uintptr_t, 0>();
  36         thrd_inst_act_map = new SnapVector<inst_act_map_t *>();
  37
  38         //values_may_read_from = new value_set_t();
  39 }
  40
  41 /* Check whether FuncInst with the same type, position, and location
  42  * as act has been added to func_inst_map or not. If not, add it.
  43  *
  44  * Note: currently, actions with the same position are filtered out by process_action,
  45  * so the collision list of FuncInst is not used. May remove it later.
  46  */
  47 void FuncNode::add_inst(ModelAction *act)
  48 {
  49         ASSERT(act);
  50         const char * position = act->get_position();
  51
  52         /* THREAD* actions, ATOMIC_LOCK, ATOMIC_TRYLOCK, and ATOMIC_UNLOCK
  53          * actions are not tagged with their source line numbers
  54          */
  55         if (position == NULL)
  56                 return;
  57
  58         if ( func_inst_map.contains(position) ) {
  59                 FuncInst * inst = func_inst_map.get(position);
  60
  61                 ASSERT(inst->get_type() == act->get_type());
  62
  63                 // locations are set to NULL when new executions start
  64                 if (inst->get_location() == NULL)
  65                         inst->set_location(act->get_location());
  66
  67                 if (inst->get_location() != act->get_location())
  68                         inst->not_single_location();
  69
  70                 return;
  71         }
  72
  73         FuncInst * func_inst = new FuncInst(act, this);
  74
  75         func_inst_map.put(position, func_inst);
  76         inst_list.push_back(func_inst);
  77 }
  78
  79 /* Get the FuncInst with the same type, position, and location
  80  * as act
  81  *
  82  * @return FuncInst with the same type, position, and location as act */
  83 FuncInst * FuncNode::get_inst(ModelAction *act)
  84 {
  85         ASSERT(act);
  86         const char * position = act->get_position();
  87
  88         /* THREAD* actions, ATOMIC_LOCK, ATOMIC_TRYLOCK, and ATOMIC_UNLOCK
  89          * actions are not tagged with their source line numbers
  90          */
  91         if (position == NULL)
  92                 return NULL;
  93
  94         FuncInst * inst = func_inst_map.get(position);
  95         if (inst == NULL)
  96                 return NULL;
  97
  98         action_type inst_type = inst->get_type();
  99         action_type act_type = act->get_type();
 100
 101         // else if branch: an RMWRCAS action is converted to a RMW or READ action
 102         if (inst_type == act_type)
 103                 return inst;
 104         else if (inst_type == ATOMIC_RMWRCAS &&
 105                         (act_type == ATOMIC_RMW || act_type == ATOMIC_READ))
 106                 return inst;
 107
 108         return NULL;
 109 }
 110
 111
 112 void FuncNode::add_entry_inst(FuncInst * inst)
 113 {
 114         if (inst == NULL)
 115                 return;
 116
 117         mllnode<FuncInst *> * it;
 118         for (it = entry_insts.begin(); it != NULL; it = it->getNext()) {
 119                 if (inst == it->getVal())
 120                         return;
 121         }
 122
 123         entry_insts.push_back(inst);
 124 }
 125
 126 /**
 127  * @brief Convert ModelAdtion list to FuncInst list
 128  * @param act_list A list of ModelActions
 129  */
 130 void FuncNode::update_tree(action_list_t * act_list)
 131 {
 132         if (act_list == NULL || act_list->size() == 0)
 133                 return;
 134
 135         HashTable<void *, value_set_t *, uintptr_t, 4> * write_history = history->getWriteHistory();
 136
 137         /* build inst_list from act_list for later processing */
 138         func_inst_list_t inst_list;
 139         action_list_t read_act_list;
 140
 141         for (sllnode<ModelAction *> * it = act_list->begin(); it != NULL; it = it->getNext()) {
 142                 ModelAction * act = it->getVal();
 143                 FuncInst * func_inst = get_inst(act);
 144
 145                 if (func_inst == NULL)
 146                         continue;
 147
 148                 inst_list.push_back(func_inst);
 149
 150                 if (func_inst->is_read()) {
 151                         read_act_list.push_back(act);
 152
 153                         /* If func_inst may only read_from a single location, then:
 154                          *
 155                          * The first time an action reads from some location, import all the values that have
 156                          * been written to this location from ModelHistory and notify ModelHistory that this
 157                          * FuncNode may read from this location.
 158                          */
 159                         void * loc = act->get_location();
 160                         if (!read_locations->contains(loc) && func_inst->is_single_location()) {
 161                                 read_locations->add(loc);
 162                                 value_set_t * write_values = write_history->get(loc);
 163                                 add_to_val_loc_map(write_values, loc);
 164                                 history->add_to_loc_func_nodes_map(loc, this);
 165                         }
 166                 }
 167         }
 168
 169 //      model_print("function %s\n", func_name);
 170 //      print_val_loc_map();
 171
 172         update_inst_tree(&inst_list);
 173         update_predicate_tree(&read_act_list);
 174
 175 //      print_predicate_tree();
 176 }
 177
 178 /**
 179  * @brief Link FuncInsts in inst_list  - add one FuncInst to another's predecessors and successors
 180  * @param inst_list A list of FuncInsts
 181  */
 182 void FuncNode::update_inst_tree(func_inst_list_t * inst_list)
 183 {
 184         if (inst_list == NULL)
 185                 return;
 186         else if (inst_list->size() == 0)
 187                 return;
 188
 189         /* start linking */
 190         sllnode<FuncInst *>* it = inst_list->begin();
 191         sllnode<FuncInst *>* prev;
 192
 193         /* add the first instruction to the list of entry insts */
 194         FuncInst * entry_inst = it->getVal();
 195         add_entry_inst(entry_inst);
 196
 197         it = it->getNext();
 198         while (it != NULL) {
 199                 prev = it->getPrev();
 200
 201                 FuncInst * prev_inst = prev->getVal();
 202                 FuncInst * curr_inst = it->getVal();
 203
 204                 prev_inst->add_succ(curr_inst);
 205                 curr_inst->add_pred(prev_inst);
 206
 207                 it = it->getNext();
 208         }
 209 }
 210
 211 void FuncNode::update_predicate_tree(action_list_t * act_list)
 212 {
 213         if (act_list == NULL || act_list->size() == 0)
 214                 return;
 215
 216         /* map a FuncInst to the its predicate */
 217         HashTable<FuncInst *, Predicate *, uintptr_t, 0> inst_pred_map(128);
 218
 219         // number FuncInsts to detect loops
 220         HashTable<FuncInst *, uint32_t, uintptr_t, 0> inst_id_map(128);
 221         uint32_t inst_counter = 0;
 222
 223         HashTable<void *, ModelAction *, uintptr_t, 0> loc_act_map(128);
 224         HashTable<FuncInst *, ModelAction *, uintptr_t, 0> inst_act_map(128);
 225
 226         sllnode<ModelAction *> *it = act_list->begin();
 227         Predicate * curr_pred = predicate_tree_entry;
 228         while (it != NULL) {
 229                 ModelAction * next_act = it->getVal();
 230                 FuncInst * next_inst = get_inst(next_act);
 231
 232                 SnapVector<Predicate *> unset_predicates = SnapVector<Predicate *>();
 233                 bool branch_found = follow_branch(&curr_pred, next_inst, next_act, &inst_act_map, &unset_predicates);
 234
 235                 // no predicate expressions
 236                 if (!branch_found && unset_predicates.size() != 0) {
 237                         ASSERT(unset_predicates.size() == 1);
 238                         Predicate * one_branch = unset_predicates[0];
 239
 240                         bool amended = amend_predicate_expr(&curr_pred, next_inst, next_act);
 241                         if (amended)
 242                                 continue;
 243                         else {
 244                                 curr_pred = one_branch;
 245                                 branch_found = true;
 246                         }
 247                 }
 248
 249                 // detect loops
 250                 if (!branch_found && inst_id_map.contains(next_inst)) {
 251                         FuncInst * curr_inst = curr_pred->get_func_inst();
 252                         uint32_t curr_id = inst_id_map.get(curr_inst);
 253                         uint32_t next_id = inst_id_map.get(next_inst);
 254
 255                         if (curr_id >= next_id) {
 256                                 Predicate * old_pred = inst_pred_map.get(next_inst);
 257                                 Predicate * back_pred = old_pred->get_parent();
 258
 259                                 curr_pred->add_backedge(back_pred);
 260                                 curr_pred = back_pred;
 261
 262                                 continue;
 263                         }
 264                 }
 265
 266                 // generate new branches
 267                 if (!branch_found) {
 268                         SnapVector<struct half_pred_expr *> half_pred_expressions;
 269                         void * loc = next_act->get_location();
 270
 271                         if ( loc_act_map.contains(loc) ) {
 272                                 ModelAction * last_act = loc_act_map.get(loc);
 273                                 FuncInst * last_inst = get_inst(last_act);
 274                                 struct half_pred_expr * expression = new half_pred_expr(EQUALITY, last_inst);
 275                                 half_pred_expressions.push_back(expression);
 276                         } else if ( next_inst->is_single_location() ){
 277                                 loc_set_t * loc_may_equal = loc_may_equal_map->get(loc);
 278
 279                                 if (loc_may_equal != NULL) {
 280                                         loc_set_iter * loc_it = loc_may_equal->iterator();
 281                                         while (loc_it->hasNext()) {
 282                                                 void * neighbor = loc_it->next();
 283                                                 if (loc_act_map.contains(neighbor)) {
 284                                                         ModelAction * last_act = loc_act_map.get(neighbor);
 285                                                         FuncInst * last_inst = get_inst(last_act);
 286
 287                                                         struct half_pred_expr * expression = new half_pred_expr(EQUALITY, last_inst);
 288                                                         half_pred_expressions.push_back(expression);
 289                                                 }
 290                                         }
 291                                 }
 292                         } else {
 293                                 // next_inst is not single location
 294                                 uint64_t read_val = next_act->get_reads_from_value();
 295
 296                                 // only generate NULLITY predicate when it is actually NULL.
 297                                 if ( (void*)read_val == NULL) {
 298                                         struct half_pred_expr * expression = new half_pred_expr(NULLITY, NULL);
 299                                         half_pred_expressions.push_back(expression);
 300                                 }
 301                         }
 302
 303                         if (half_pred_expressions.size() == 0) {
 304                                 // no predicate needs to be generated
 305                                 Predicate * new_pred = new Predicate(next_inst);
 306                                 curr_pred->add_child(new_pred);
 307                                 new_pred->set_parent(curr_pred);
 308
 309                                 if (curr_pred->is_entry_predicate())
 310                                         new_pred->add_predicate_expr(NOPREDICATE, NULL, true);
 311
 312                                 curr_pred = new_pred;
 313                         } else {
 314                                 generate_predicate(&curr_pred, next_inst, &half_pred_expressions);
 315                                 bool branch_found = follow_branch(&curr_pred, next_inst, next_act, &inst_act_map, NULL);
 316                                 ASSERT(branch_found);
 317                         }
 318                 }
 319
 320                 inst_pred_map.put(next_inst, curr_pred);
 321                 if (!inst_id_map.contains(next_inst))
 322                         inst_id_map.put(next_inst, inst_counter++);
 323
 324                 loc_act_map.put(next_act->get_location(), next_act);
 325                 inst_act_map.put(next_inst, next_act);
 326                 it = it->getNext();
 327         }
 328 }
 329
 330 /* Given curr_pred and next_inst, find the branch following curr_pred that
 331  * contains next_inst and the correct predicate.
 332  * @return true if branch found, false otherwise.
 333  */
 334 bool FuncNode::follow_branch(Predicate ** curr_pred, FuncInst * next_inst, ModelAction * next_act,
 335         HashTable<FuncInst *, ModelAction *, uintptr_t, 0> * inst_act_map,
 336         SnapVector<Predicate *> * unset_predicates)
 337 {
 338         /* check if a branch with func_inst and corresponding predicate exists */
 339         bool branch_found = false;
 340         ModelVector<Predicate *> * branches = (*curr_pred)->get_children();
 341         for (uint i = 0; i < branches->size(); i++) {
 342                 Predicate * branch = (*branches)[i];
 343                 if (branch->get_func_inst() != next_inst)
 344                         continue;
 345
 346                 /* check against predicate expressions */
 347                 bool predicate_correct = true;
 348                 PredExprSet * pred_expressions = branch->get_pred_expressions();
 349                 PredExprSetIter * pred_expr_it = pred_expressions->iterator();
 350
 351                 if (pred_expressions->getSize() == 0) {
 352                         predicate_correct = false;
 353                         unset_predicates->push_back(branch);
 354                 }
 355
 356                 while (pred_expr_it->hasNext()) {
 357                         pred_expr * pred_expression = pred_expr_it->next();
 358                         uint64_t last_read, next_read;
 359                         bool equality;
 360
 361                         switch(pred_expression->token) {
 362                                 case NOPREDICATE:
 363                                         predicate_correct = true;
 364                                         break;
 365                                 case EQUALITY:
 366                                         FuncInst * to_be_compared;
 367                                         ModelAction * last_act;
 368
 369                                         to_be_compared = pred_expression->func_inst;
 370                                         last_act = inst_act_map->get(to_be_compared);
 371
 372                                         last_read = last_act->get_reads_from_value();
 373                                         next_read = next_act->get_reads_from_value();
 374                                         equality = (last_read == next_read);
 375                                         if (equality != pred_expression->value)
 376                                                 predicate_correct = false;
 377
 378                                         break;
 379                                 case NULLITY:
 380                                         next_read = next_act->get_reads_from_value();
 381                                         equality = ((void*)next_read == NULL);
 382                                         if (equality != pred_expression->value)
 383                                                 predicate_correct = false;
 384                                         break;
 385                                 default:
 386                                         predicate_correct = false;
 387                                         model_print("unkown predicate token\n");
 388                                         break;
 389                         }
 390                 }
 391
 392                 if (predicate_correct) {
 393                         *curr_pred = branch;
 394                         branch_found = true;
 395                         break;
 396                 }
 397         }
 398
 399         return branch_found;
 400 }
 401
 402 /* Able to generate complex predicates when there are multiple predciate expressions */
 403 void FuncNode::generate_predicate(Predicate ** curr_pred, FuncInst * next_inst,
 404         SnapVector<struct half_pred_expr *> * half_pred_expressions)
 405 {
 406         ASSERT(half_pred_expressions->size() != 0);
 407         SnapVector<Predicate *> predicates;
 408
 409         struct half_pred_expr * half_expr = (*half_pred_expressions)[0];
 410         predicates.push_back(new Predicate(next_inst));
 411         predicates.push_back(new Predicate(next_inst));
 412
 413         predicates[0]->add_predicate_expr(half_expr->token, half_expr->func_inst, true);
 414         predicates[1]->add_predicate_expr(half_expr->token, half_expr->func_inst, false);
 415
 416         for (uint i = 1; i < half_pred_expressions->size(); i++) {
 417                 half_expr = (*half_pred_expressions)[i];
 418
 419                 uint old_size = predicates.size();
 420                 for (uint j = 0; j < old_size; j++) {
 421                         Predicate * pred = predicates[j];
 422                         Predicate * new_pred = new Predicate(next_inst);
 423                         new_pred->copy_predicate_expr(pred);
 424
 425                         pred->add_predicate_expr(half_expr->token, half_expr->func_inst, true);
 426                         new_pred->add_predicate_expr(half_expr->token, half_expr->func_inst, false);
 427
 428                         predicates.push_back(new_pred);
 429                 }
 430         }
 431
 432         for (uint i = 0; i < predicates.size(); i++) {
 433                 Predicate * pred= predicates[i];
 434                 (*curr_pred)->add_child(pred);
 435                 pred->set_parent(*curr_pred);
 436         }
 437 }
 438
 439 /* Amend predicates that contain no predicate expressions. Currenlty only amend with NULLITY predicates */
 440 bool FuncNode::amend_predicate_expr(Predicate ** curr_pred, FuncInst * next_inst, ModelAction * next_act)
 441 {
 442         // there should only be only child
 443         Predicate * unset_pred = (*curr_pred)->get_children()->back();
 444         uint64_t read_val = next_act->get_reads_from_value();
 445
 446         // only generate NULLITY predicate when it is actually NULL.
 447         if ( !next_inst->is_single_location() && (void*)read_val == NULL ) {
 448                 Predicate * new_pred = new Predicate(next_inst);
 449
 450                 (*curr_pred)->add_child(new_pred);
 451                 new_pred->set_parent(*curr_pred);
 452
 453                 unset_pred->add_predicate_expr(NULLITY, NULL, false);
 454                 new_pred->add_predicate_expr(NULLITY, NULL, true);
 455
 456                 return true;
 457         }
 458
 459         return false;
 460 }
 461
 462 void FuncNode::add_to_val_loc_map(uint64_t val, void * loc)
 463 {
 464         loc_set_t * locations = val_loc_map->get(val);
 465
 466         if (locations == NULL) {
 467                 locations = new loc_set_t();
 468                 val_loc_map->put(val, locations);
 469         }
 470
 471         update_loc_may_equal_map(loc, locations);
 472         locations->add(loc);
 473         // values_may_read_from->add(val);
 474 }
 475
 476 void FuncNode::add_to_val_loc_map(value_set_t * values, void * loc)
 477 {
 478         if (values == NULL)
 479                 return;
 480
 481         value_set_iter * it = values->iterator();
 482         while (it->hasNext()) {
 483                 uint64_t val = it->next();
 484                 add_to_val_loc_map(val, loc);
 485         }
 486 }
 487
 488 void FuncNode::update_loc_may_equal_map(void * new_loc, loc_set_t * old_locations)
 489 {
 490         if ( old_locations->contains(new_loc) )
 491                 return;
 492
 493         loc_set_t * neighbors = loc_may_equal_map->get(new_loc);
 494
 495         if (neighbors == NULL) {
 496                 neighbors = new loc_set_t();
 497                 loc_may_equal_map->put(new_loc, neighbors);
 498         }
 499
 500         loc_set_iter * loc_it = old_locations->iterator();
 501         while (loc_it->hasNext()) {
 502                 // new_loc: { old_locations, ... }
 503                 void * member = loc_it->next();
 504                 neighbors->add(member);
 505
 506                 // for each i in old_locations, i : { new_loc, ... }
 507                 loc_set_t * _neighbors = loc_may_equal_map->get(member);
 508                 if (_neighbors == NULL) {
 509                         _neighbors = new loc_set_t();
 510                         loc_may_equal_map->put(member, _neighbors);
 511                 }
 512                 _neighbors->add(new_loc);
 513         }
 514 }
 515
 516 void FuncNode::init_predicate_tree_position(thread_id_t tid)
 517 {
 518         int thread_id = id_to_int(tid);
 519         if (predicate_tree_position.size() <= (uint) thread_id)
 520                 predicate_tree_position.resize(thread_id + 1);
 521
 522         predicate_tree_position[thread_id] = predicate_tree_entry;
 523 }
 524
 525 void FuncNode::set_predicate_tree_position(thread_id_t tid, Predicate * pred)
 526 {
 527         int thread_id = id_to_int(tid);
 528         predicate_tree_position[thread_id] = pred;
 529 }
 530
 531 Predicate * FuncNode::get_predicate_tree_position(thread_id_t tid)
 532 {
 533         int thread_id = id_to_int(tid);
 534         return predicate_tree_position[thread_id];
 535 }
 536
 537 void FuncNode::init_inst_act_map(thread_id_t tid)
 538 {
 539         int thread_id = id_to_int(tid);
 540         uint old_size = thrd_inst_act_map->size();
 541
 542         if (thrd_inst_act_map->size() <= (uint) thread_id) {
 543                 uint new_size = thread_id + 1;
 544                 thrd_inst_act_map->resize(new_size);
 545
 546                 for (uint i = old_size; i < new_size; i++)
 547                         (*thrd_inst_act_map)[i] = new inst_act_map_t(128);
 548         }
 549 }
 550
 551 void FuncNode::reset_inst_act_map(thread_id_t tid)
 552 {
 553         int thread_id = id_to_int(tid);
 554         inst_act_map_t * map = (*thrd_inst_act_map)[thread_id];
 555         map->reset();
 556 }
 557
 558 void FuncNode::update_inst_act_map(thread_id_t tid, ModelAction * read_act)
 559 {
 560         int thread_id = id_to_int(tid);
 561         inst_act_map_t * map = (*thrd_inst_act_map)[thread_id];
 562         FuncInst * read_inst = get_inst(read_act);
 563         map->put(read_inst, read_act);
 564 }
 565
 566 inst_act_map_t * FuncNode::get_inst_act_map(thread_id_t tid)
 567 {
 568         int thread_id = id_to_int(tid);
 569         return (*thrd_inst_act_map)[thread_id];
 570 }
 571
 572 void FuncNode::print_predicate_tree()
 573 {
 574         model_print("digraph function_%s {\n", func_name);
 575         predicate_tree_entry->print_pred_subtree();
 576         model_print("}\n");     // end of graph
 577 }
 578
 579 void FuncNode::print_val_loc_map()
 580 {
 581 /*
 582         value_set_iter * val_it = values_may_read_from->iterator();
 583         while (val_it->hasNext()) {
 584                 uint64_t value = val_it->next();
 585                 model_print("val %llx: ", value);
 586
 587                 loc_set_t * locations = val_loc_map->get(value);
 588                 loc_set_iter * loc_it = locations->iterator();
 589                 while (loc_it->hasNext()) {
 590                         void * location = loc_it->next();
 591                         model_print("%p ", location);
 592                 }
 593                 model_print("\n");
 594         }
 595 */
 596 }